[PATCHv4,1/3] target/configfs: add module wide action support
diff mbox

Message ID 1524123964-21347-2-git-send-email-xiubli@redhat.com
State New, archived
Headers show

Commit Message

Xiubo Li April 19, 2018, 7:46 a.m. UTC
From: Xiubo Li <xiubli@redhat.com>

For some case we need some module wide configfs to contol some
attributes of the whole transport module.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 drivers/target/target_core_configfs.c | 46 +++++++++++++++++++++++++++++++++++
 drivers/target/target_core_hba.c      | 11 +++++++++
 drivers/target/target_core_internal.h |  5 ++++
 include/target/target_core_backend.h  |  1 +
 4 files changed, 63 insertions(+)

Comments

Mike Christie May 2, 2018, 6:27 p.m. UTC | #1
On 04/19/2018 02:46 AM, xiubli@redhat.com wrote:
> From: Xiubo Li <xiubli@redhat.com>
> 
> For some case we need some module wide configfs to contol some
> attributes of the whole transport module.

When I suggested to move it module wide I just meant to add another mod
param like the global max data area param. I like the approach below
though, because rtslib can work similar to how it does for other
objects. However for tcmu we will have a mix of types, so I am not sure
how you are going to deal with compat. Maybe add a module level attrs
attr and add a max data area there that calls the same mod param code.
There would still be a kernel where it is not supported though.

Add some comments below if we go this route.


> 
> Signed-off-by: Xiubo Li <xiubli@redhat.com>
> ---
>  drivers/target/target_core_configfs.c | 46 +++++++++++++++++++++++++++++++++++
>  drivers/target/target_core_hba.c      | 11 +++++++++
>  drivers/target/target_core_internal.h |  5 ++++
>  include/target/target_core_backend.h  |  1 +
>  4 files changed, 63 insertions(+)
> 
> diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
> index 3f4bf12..a1ee716 100644
> --- a/drivers/target/target_core_configfs.c
> +++ b/drivers/target/target_core_configfs.c
> @@ -79,6 +79,7 @@
>  static struct config_group target_core_hbagroup;
>  static struct config_group alua_group;
>  static struct config_group alua_lu_gps_group;
> +static struct config_group action_group;
>  
>  static inline struct se_hba *
>  item_to_hba(struct config_item *item)
> @@ -1198,6 +1199,7 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
>  
>  TB_CIT_SETUP_DRV(dev_attrib, NULL, NULL);
>  TB_CIT_SETUP_DRV(dev_action, NULL, NULL);
> +TB_CIT_SETUP_DRV(mod_action, NULL, NULL);
>  
>  /* End functions for struct config_item_type tb_dev_attrib_cit */
>  
> @@ -2893,6 +2895,20 @@ static void target_core_alua_drop_tg_pt_gp(
>  
>  /* End functions for struct config_item_type target_core_alua_cit */
>  
> +/* Start functions for struct config_item_type target_core_action_cit */
> +
> +/*
> + * target_core_action_cit is a ConfigFS group that lives under
> + * /sys/kernel/config/target/core/action.
> + */
> +static const struct config_item_type target_core_action_cit = {
> +	.ct_item_ops		= NULL,
> +	.ct_attrs		= NULL,
> +	.ct_owner		= THIS_MODULE,
> +};
> +
> +/* End functions for struct config_item_type target_core_action_cit */
> +
>  /* Start functions for struct config_item_type tb_dev_stat_cit */
>  
>  static struct config_group *target_core_stat_mkdir(
> @@ -3211,6 +3227,30 @@ void target_setup_backend_cits(struct target_backend *tb)
>  	target_core_setup_dev_wwn_cit(tb);
>  	target_core_setup_dev_alua_tg_pt_gps_cit(tb);
>  	target_core_setup_dev_stat_cit(tb);
> +
> +	target_core_setup_mod_action_cit(tb);
> +}
> +
> +int target_setup_backend_action(struct target_backend *tb)


I think it might be best to rename these to:

target_register_backend_action_group
target_unregister_backend_action_group

It seems we are doing the setup and un/registration and unset is not a
common name type in the existing code.



> +{
> +	if (!tb->ops->tb_mod_action_attrs)
> +		return 0;
> +
> +	tb->action_group = configfs_register_default_group(&action_group,
> +						tb->ops->name,
> +						&tb->tb_mod_action_cit);
> +	if (!tb->action_group)

I think you need to do

if (IS_ERR(tb->action_group))


> +		return PTR_ERR(tb->action_group);
> +
> +	return 0;
> +}
> +
> +void target_unset_backend_action(struct target_backend *tb)
> +{
> +	if (!tb->ops->tb_mod_action_attrs)
> +		return;
> +
> +	configfs_unregister_default_group(tb->action_group);
>  }
>  
>  static int __init target_core_init_configfs(void)
> @@ -3267,6 +3307,12 @@ static int __init target_core_init_configfs(void)
>  	default_lu_gp = lu_gp;
>  
>  	/*
> +	 * Create ALUA infrastructure under /sys/kernel/config/target/core/action/

Fix up the ALUA reference in the comment.

> +	 */
> +	config_group_init_type_name(&action_group, "action", &target_core_action_cit);
> +	configfs_add_default_group(&action_group, &target_core_hbagroup);
> +
> +	/*
>  	 * Register the target_core_mod subsystem with configfs.
>  	 */
>  	ret = configfs_register_subsystem(subsys);
> diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
> index 22390e0..6903087 100644
> --- a/drivers/target/target_core_hba.c
> +++ b/drivers/target/target_core_hba.c
> @@ -51,6 +51,7 @@
>  int transport_backend_register(const struct target_backend_ops *ops)
>  {
>  	struct target_backend *tb, *old;
> +	int ret;
>  
>  	tb = kzalloc(sizeof(*tb), GFP_KERNEL);
>  	if (!tb)
> @@ -67,11 +68,20 @@ int transport_backend_register(const struct target_backend_ops *ops)
>  		}
>  	}
>  	target_setup_backend_cits(tb);
> +
> +	ret = target_setup_backend_action(tb);
> +	if (ret) {
> +		mutex_unlock(&backend_mutex);
> +		kfree(tb);

Just do a goto since we have multiple places doing the same cleanup with
this addition.

> +		return ret;
> +	}
> +
>  	list_add_tail(&tb->list, &backend_list);
>  	mutex_unlock(&backend_mutex);
>  
>  	pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
>  			ops->name, ops->owner);
> +

Don't add extra formatting.

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Xiubo Li May 3, 2018, 12:54 a.m. UTC | #2
On 2018/5/3 2:27, Mike Christie wrote:
> On 04/19/2018 02:46 AM, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>> For some case we need some module wide configfs to contol some
>> attributes of the whole transport module.
> When I suggested to move it module wide I just meant to add another mod
> param like the global max data area param. I like the approach below
> though, because rtslib can work similar to how it does for other
> objects. However for tcmu we will have a mix of types, so I am not sure
> how you are going to deal with compat. Maybe add a module level attrs
> attr and add a max data area there that calls the same mod param code.
> There would still be a kernel where it is not supported though.
Hey Mike,

I just thought currently approach will be more flexible.
Yeah,  for the compat issue it should be a little painful to deal with. 
It's up to you and I am okay for both approaches.

BRs
Thanks,




> Add some comments below if we go this route.
>
>
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>   drivers/target/target_core_configfs.c | 46 +++++++++++++++++++++++++++++++++++
>>   drivers/target/target_core_hba.c      | 11 +++++++++
>>   drivers/target/target_core_internal.h |  5 ++++
>>   include/target/target_core_backend.h  |  1 +
>>   4 files changed, 63 insertions(+)
>>
>> diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
>> index 3f4bf12..a1ee716 100644
>> --- a/drivers/target/target_core_configfs.c
>> +++ b/drivers/target/target_core_configfs.c
>> @@ -79,6 +79,7 @@
>>   static struct config_group target_core_hbagroup;
>>   static struct config_group alua_group;
>>   static struct config_group alua_lu_gps_group;
>> +static struct config_group action_group;
>>   
>>   static inline struct se_hba *
>>   item_to_hba(struct config_item *item)
>> @@ -1198,6 +1199,7 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
>>   
>>   TB_CIT_SETUP_DRV(dev_attrib, NULL, NULL);
>>   TB_CIT_SETUP_DRV(dev_action, NULL, NULL);
>> +TB_CIT_SETUP_DRV(mod_action, NULL, NULL);
>>   
>>   /* End functions for struct config_item_type tb_dev_attrib_cit */
>>   
>> @@ -2893,6 +2895,20 @@ static void target_core_alua_drop_tg_pt_gp(
>>   
>>   /* End functions for struct config_item_type target_core_alua_cit */
>>   
>> +/* Start functions for struct config_item_type target_core_action_cit */
>> +
>> +/*
>> + * target_core_action_cit is a ConfigFS group that lives under
>> + * /sys/kernel/config/target/core/action.
>> + */
>> +static const struct config_item_type target_core_action_cit = {
>> +	.ct_item_ops		= NULL,
>> +	.ct_attrs		= NULL,
>> +	.ct_owner		= THIS_MODULE,
>> +};
>> +
>> +/* End functions for struct config_item_type target_core_action_cit */
>> +
>>   /* Start functions for struct config_item_type tb_dev_stat_cit */
>>   
>>   static struct config_group *target_core_stat_mkdir(
>> @@ -3211,6 +3227,30 @@ void target_setup_backend_cits(struct target_backend *tb)
>>   	target_core_setup_dev_wwn_cit(tb);
>>   	target_core_setup_dev_alua_tg_pt_gps_cit(tb);
>>   	target_core_setup_dev_stat_cit(tb);
>> +
>> +	target_core_setup_mod_action_cit(tb);
>> +}
>> +
>> +int target_setup_backend_action(struct target_backend *tb)
>
> I think it might be best to rename these to:
>
> target_register_backend_action_group
> target_unregister_backend_action_group
>
> It seems we are doing the setup and un/registration and unset is not a
> common name type in the existing code.
>
>
>
>> +{
>> +	if (!tb->ops->tb_mod_action_attrs)
>> +		return 0;
>> +
>> +	tb->action_group = configfs_register_default_group(&action_group,
>> +						tb->ops->name,
>> +						&tb->tb_mod_action_cit);
>> +	if (!tb->action_group)
> I think you need to do
>
> if (IS_ERR(tb->action_group))
>
>
>> +		return PTR_ERR(tb->action_group);
>> +
>> +	return 0;
>> +}
>> +
>> +void target_unset_backend_action(struct target_backend *tb)
>> +{
>> +	if (!tb->ops->tb_mod_action_attrs)
>> +		return;
>> +
>> +	configfs_unregister_default_group(tb->action_group);
>>   }
>>   
>>   static int __init target_core_init_configfs(void)
>> @@ -3267,6 +3307,12 @@ static int __init target_core_init_configfs(void)
>>   	default_lu_gp = lu_gp;
>>   
>>   	/*
>> +	 * Create ALUA infrastructure under /sys/kernel/config/target/core/action/
> Fix up the ALUA reference in the comment.
>
>> +	 */
>> +	config_group_init_type_name(&action_group, "action", &target_core_action_cit);
>> +	configfs_add_default_group(&action_group, &target_core_hbagroup);
>> +
>> +	/*
>>   	 * Register the target_core_mod subsystem with configfs.
>>   	 */
>>   	ret = configfs_register_subsystem(subsys);
>> diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
>> index 22390e0..6903087 100644
>> --- a/drivers/target/target_core_hba.c
>> +++ b/drivers/target/target_core_hba.c
>> @@ -51,6 +51,7 @@
>>   int transport_backend_register(const struct target_backend_ops *ops)
>>   {
>>   	struct target_backend *tb, *old;
>> +	int ret;
>>   
>>   	tb = kzalloc(sizeof(*tb), GFP_KERNEL);
>>   	if (!tb)
>> @@ -67,11 +68,20 @@ int transport_backend_register(const struct target_backend_ops *ops)
>>   		}
>>   	}
>>   	target_setup_backend_cits(tb);
>> +
>> +	ret = target_setup_backend_action(tb);
>> +	if (ret) {
>> +		mutex_unlock(&backend_mutex);
>> +		kfree(tb);
> Just do a goto since we have multiple places doing the same cleanup with
> this addition.
>
>> +		return ret;
>> +	}
>> +
>>   	list_add_tail(&tb->list, &backend_list);
>>   	mutex_unlock(&backend_mutex);
>>   
>>   	pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
>>   			ops->name, ops->owner);
>> +
> Don't add extra formatting.
>
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


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Xiubo Li May 3, 2018, 1:03 a.m. UTC | #3
On 2018/5/3 2:27, Mike Christie wrote:
> On 04/19/2018 02:46 AM, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>> For some case we need some module wide configfs to contol some
>> attributes of the whole transport module.
> When I suggested to move it module wide I just meant to add another mod
> param like the global max data area param. I like the approach below
> though, because rtslib can work similar to how it does for other
> objects. However for tcmu we will have a mix of types, so I am not sure
> how you are going to deal with compat. Maybe add a module level attrs
> attr and add a max data area there that calls the same mod param code.
> There would still be a kernel where it is not supported though.
But from currently after the tcmu-runner is crashed the 
target_core_user.ko will still be kept inserted, something like:

[root@gblock2 ~]# lsmod |grep target
target_core_pscsi      18799  0
target_core_file       18217  0
target_core_iblock     18282  0
iscsi_target_mod      291661  8
target_core_user       24557  2
target_core_mod       340729  18 
target_core_iblock,target_core_pscsi,iscsi_target_mod,target_core_file,target_core_user
uio                    19259  1 target_core_user
crc_t10dif             12912  2 target_core_mod,sd_mod

If make it a mod param, like this issue how could it be work when the 
tcmu-runner is crashed and try to start again?

BRs


> Add some comments below if we go this route.
>
>
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>   drivers/target/target_core_configfs.c | 46 +++++++++++++++++++++++++++++++++++
>>   drivers/target/target_core_hba.c      | 11 +++++++++
>>   drivers/target/target_core_internal.h |  5 ++++
>>   include/target/target_core_backend.h  |  1 +
>>   4 files changed, 63 insertions(+)
>>
>> diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
>> index 3f4bf12..a1ee716 100644
>> --- a/drivers/target/target_core_configfs.c
>> +++ b/drivers/target/target_core_configfs.c
>> @@ -79,6 +79,7 @@
>>   static struct config_group target_core_hbagroup;
>>   static struct config_group alua_group;
>>   static struct config_group alua_lu_gps_group;
>> +static struct config_group action_group;
>>   
>>   static inline struct se_hba *
>>   item_to_hba(struct config_item *item)
>> @@ -1198,6 +1199,7 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
>>   
>>   TB_CIT_SETUP_DRV(dev_attrib, NULL, NULL);
>>   TB_CIT_SETUP_DRV(dev_action, NULL, NULL);
>> +TB_CIT_SETUP_DRV(mod_action, NULL, NULL);
>>   
>>   /* End functions for struct config_item_type tb_dev_attrib_cit */
>>   
>> @@ -2893,6 +2895,20 @@ static void target_core_alua_drop_tg_pt_gp(
>>   
>>   /* End functions for struct config_item_type target_core_alua_cit */
>>   
>> +/* Start functions for struct config_item_type target_core_action_cit */
>> +
>> +/*
>> + * target_core_action_cit is a ConfigFS group that lives under
>> + * /sys/kernel/config/target/core/action.
>> + */
>> +static const struct config_item_type target_core_action_cit = {
>> +	.ct_item_ops		= NULL,
>> +	.ct_attrs		= NULL,
>> +	.ct_owner		= THIS_MODULE,
>> +};
>> +
>> +/* End functions for struct config_item_type target_core_action_cit */
>> +
>>   /* Start functions for struct config_item_type tb_dev_stat_cit */
>>   
>>   static struct config_group *target_core_stat_mkdir(
>> @@ -3211,6 +3227,30 @@ void target_setup_backend_cits(struct target_backend *tb)
>>   	target_core_setup_dev_wwn_cit(tb);
>>   	target_core_setup_dev_alua_tg_pt_gps_cit(tb);
>>   	target_core_setup_dev_stat_cit(tb);
>> +
>> +	target_core_setup_mod_action_cit(tb);
>> +}
>> +
>> +int target_setup_backend_action(struct target_backend *tb)
>
> I think it might be best to rename these to:
>
> target_register_backend_action_group
> target_unregister_backend_action_group
>
> It seems we are doing the setup and un/registration and unset is not a
> common name type in the existing code.
>
>
>
>> +{
>> +	if (!tb->ops->tb_mod_action_attrs)
>> +		return 0;
>> +
>> +	tb->action_group = configfs_register_default_group(&action_group,
>> +						tb->ops->name,
>> +						&tb->tb_mod_action_cit);
>> +	if (!tb->action_group)
> I think you need to do
>
> if (IS_ERR(tb->action_group))
>
>
>> +		return PTR_ERR(tb->action_group);
>> +
>> +	return 0;
>> +}
>> +
>> +void target_unset_backend_action(struct target_backend *tb)
>> +{
>> +	if (!tb->ops->tb_mod_action_attrs)
>> +		return;
>> +
>> +	configfs_unregister_default_group(tb->action_group);
>>   }
>>   
>>   static int __init target_core_init_configfs(void)
>> @@ -3267,6 +3307,12 @@ static int __init target_core_init_configfs(void)
>>   	default_lu_gp = lu_gp;
>>   
>>   	/*
>> +	 * Create ALUA infrastructure under /sys/kernel/config/target/core/action/
> Fix up the ALUA reference in the comment.
>
>> +	 */
>> +	config_group_init_type_name(&action_group, "action", &target_core_action_cit);
>> +	configfs_add_default_group(&action_group, &target_core_hbagroup);
>> +
>> +	/*
>>   	 * Register the target_core_mod subsystem with configfs.
>>   	 */
>>   	ret = configfs_register_subsystem(subsys);
>> diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
>> index 22390e0..6903087 100644
>> --- a/drivers/target/target_core_hba.c
>> +++ b/drivers/target/target_core_hba.c
>> @@ -51,6 +51,7 @@
>>   int transport_backend_register(const struct target_backend_ops *ops)
>>   {
>>   	struct target_backend *tb, *old;
>> +	int ret;
>>   
>>   	tb = kzalloc(sizeof(*tb), GFP_KERNEL);
>>   	if (!tb)
>> @@ -67,11 +68,20 @@ int transport_backend_register(const struct target_backend_ops *ops)
>>   		}
>>   	}
>>   	target_setup_backend_cits(tb);
>> +
>> +	ret = target_setup_backend_action(tb);
>> +	if (ret) {
>> +		mutex_unlock(&backend_mutex);
>> +		kfree(tb);
> Just do a goto since we have multiple places doing the same cleanup with
> this addition.
>
>> +		return ret;
>> +	}
>> +
>>   	list_add_tail(&tb->list, &backend_list);
>>   	mutex_unlock(&backend_mutex);
>>   
>>   	pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
>>   			ops->name, ops->owner);
>> +
> Don't add extra formatting.
>
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


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Mike Christie May 3, 2018, 3:31 p.m. UTC | #4
On 05/02/2018 08:03 PM, Xiubo Li wrote:
> On 2018/5/3 2:27, Mike Christie wrote:
>> On 04/19/2018 02:46 AM, xiubli@redhat.com wrote:
>>> From: Xiubo Li <xiubli@redhat.com>
>>>
>>> For some case we need some module wide configfs to contol some
>>> attributes of the whole transport module.
>> When I suggested to move it module wide I just meant to add another mod
>> param like the global max data area param. I like the approach below
>> though, because rtslib can work similar to how it does for other
>> objects. However for tcmu we will have a mix of types, so I am not sure
>> how you are going to deal with compat. Maybe add a module level attrs
>> attr and add a max data area there that calls the same mod param code.
>> There would still be a kernel where it is not supported though.
> But from currently after the tcmu-runner is crashed the
> target_core_user.ko will still be kept inserted, something like:
> 
> [root@gblock2 ~]# lsmod |grep target
> target_core_pscsi      18799  0
> target_core_file       18217  0
> target_core_iblock     18282  0
> iscsi_target_mod      291661  8
> target_core_user       24557  2
> target_core_mod       340729  18
> target_core_iblock,target_core_pscsi,iscsi_target_mod,target_core_file,target_core_user
> 
> uio                    19259  1 target_core_user
> crc_t10dif             12912  2 target_core_mod,sd_mod
> 
> If make it a mod param, like this issue how could it be work when the
> tcmu-runner is crashed and try to start again?

When you do a module_param_cb it creates a sysfs file in
/sys/module/target_core_user/parameters that you can read/write to like
any other sysfs file.

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Patch
diff mbox

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 3f4bf12..a1ee716 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -79,6 +79,7 @@ 
 static struct config_group target_core_hbagroup;
 static struct config_group alua_group;
 static struct config_group alua_lu_gps_group;
+static struct config_group action_group;
 
 static inline struct se_hba *
 item_to_hba(struct config_item *item)
@@ -1198,6 +1199,7 @@  struct configfs_attribute *passthrough_attrib_attrs[] = {
 
 TB_CIT_SETUP_DRV(dev_attrib, NULL, NULL);
 TB_CIT_SETUP_DRV(dev_action, NULL, NULL);
+TB_CIT_SETUP_DRV(mod_action, NULL, NULL);
 
 /* End functions for struct config_item_type tb_dev_attrib_cit */
 
@@ -2893,6 +2895,20 @@  static void target_core_alua_drop_tg_pt_gp(
 
 /* End functions for struct config_item_type target_core_alua_cit */
 
+/* Start functions for struct config_item_type target_core_action_cit */
+
+/*
+ * target_core_action_cit is a ConfigFS group that lives under
+ * /sys/kernel/config/target/core/action.
+ */
+static const struct config_item_type target_core_action_cit = {
+	.ct_item_ops		= NULL,
+	.ct_attrs		= NULL,
+	.ct_owner		= THIS_MODULE,
+};
+
+/* End functions for struct config_item_type target_core_action_cit */
+
 /* Start functions for struct config_item_type tb_dev_stat_cit */
 
 static struct config_group *target_core_stat_mkdir(
@@ -3211,6 +3227,30 @@  void target_setup_backend_cits(struct target_backend *tb)
 	target_core_setup_dev_wwn_cit(tb);
 	target_core_setup_dev_alua_tg_pt_gps_cit(tb);
 	target_core_setup_dev_stat_cit(tb);
+
+	target_core_setup_mod_action_cit(tb);
+}
+
+int target_setup_backend_action(struct target_backend *tb)
+{
+	if (!tb->ops->tb_mod_action_attrs)
+		return 0;
+
+	tb->action_group = configfs_register_default_group(&action_group,
+						tb->ops->name,
+						&tb->tb_mod_action_cit);
+	if (!tb->action_group)
+		return PTR_ERR(tb->action_group);
+
+	return 0;
+}
+
+void target_unset_backend_action(struct target_backend *tb)
+{
+	if (!tb->ops->tb_mod_action_attrs)
+		return;
+
+	configfs_unregister_default_group(tb->action_group);
 }
 
 static int __init target_core_init_configfs(void)
@@ -3267,6 +3307,12 @@  static int __init target_core_init_configfs(void)
 	default_lu_gp = lu_gp;
 
 	/*
+	 * Create ALUA infrastructure under /sys/kernel/config/target/core/action/
+	 */
+	config_group_init_type_name(&action_group, "action", &target_core_action_cit);
+	configfs_add_default_group(&action_group, &target_core_hbagroup);
+
+	/*
 	 * Register the target_core_mod subsystem with configfs.
 	 */
 	ret = configfs_register_subsystem(subsys);
diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
index 22390e0..6903087 100644
--- a/drivers/target/target_core_hba.c
+++ b/drivers/target/target_core_hba.c
@@ -51,6 +51,7 @@ 
 int transport_backend_register(const struct target_backend_ops *ops)
 {
 	struct target_backend *tb, *old;
+	int ret;
 
 	tb = kzalloc(sizeof(*tb), GFP_KERNEL);
 	if (!tb)
@@ -67,11 +68,20 @@  int transport_backend_register(const struct target_backend_ops *ops)
 		}
 	}
 	target_setup_backend_cits(tb);
+
+	ret = target_setup_backend_action(tb);
+	if (ret) {
+		mutex_unlock(&backend_mutex);
+		kfree(tb);
+		return ret;
+	}
+
 	list_add_tail(&tb->list, &backend_list);
 	mutex_unlock(&backend_mutex);
 
 	pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
 			ops->name, ops->owner);
+
 	return 0;
 }
 EXPORT_SYMBOL(transport_backend_register);
@@ -84,6 +94,7 @@  void target_backend_unregister(const struct target_backend_ops *ops)
 	list_for_each_entry(tb, &backend_list, list) {
 		if (tb->ops == ops) {
 			list_del(&tb->list);
+			target_unset_backend_action(tb);
 			mutex_unlock(&backend_mutex);
 			/*
 			 * Wait for any outstanding backend driver ->rcu_head
diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h
index 1d5afc3..73e8157 100644
--- a/drivers/target/target_core_internal.h
+++ b/drivers/target/target_core_internal.h
@@ -22,6 +22,9 @@  struct target_backend {
 	struct config_item_type tb_dev_wwn_cit;
 	struct config_item_type tb_dev_alua_tg_pt_gps_cit;
 	struct config_item_type tb_dev_stat_cit;
+
+	struct config_group *action_group;
+	struct config_item_type tb_mod_action_cit;
 };
 
 struct target_fabric_configfs {
@@ -92,6 +95,8 @@  int	target_for_each_device(int (*fn)(struct se_device *dev, void *data),
 /* target_core_configfs.c */
 extern struct configfs_item_operations target_core_dev_item_ops;
 void	target_setup_backend_cits(struct target_backend *);
+int target_setup_backend_action(struct target_backend *tb);
+void target_unset_backend_action(struct target_backend *tb);
 
 /* target_core_fabric_configfs.c */
 int	target_fabric_setup_cits(struct target_fabric_configfs *);
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 34a15d5..5df7059 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -54,6 +54,7 @@  struct target_backend_ops {
 
 	struct configfs_attribute **tb_dev_attrib_attrs;
 	struct configfs_attribute **tb_dev_action_attrs;
+	struct configfs_attribute **tb_mod_action_attrs;
 };
 
 struct sbc_ops {